2/3/317/4/5/6/635/8/10mm Boat Car Shaft Coupler Motor Connector Metal Universal Joint Coupling Rc Boat Car Metal Cardan Joint Metal joint suited to use direct axis motor, suitable for model cars, model ships, robots, and other metal adapter to use. "4mm-6mm" means "one hole diameter of the coupler is 4mm ,the other is 6mm" 2mm-2mm, 2mm-2.3mm, 2.3mm-2.3mm Universal Joint Outside Diameter: 8mm Universal Joint Length: 18mm Side Screw Fixing Hole: M3 2mm-3mm, 2mm-4mm,2.3mm-3mm,2.3mm-4mm, 3mm-3mm, 3mm-3.17mm, 3mm-4mm, 3.17mm-3.17mm, 3.17mm-4mm, 4mm-4mm Universal Joint Outside Diameter: 9mm Universal Joint Length: 23mm Side Screw Fixing Hole: M3 3mm-5mm, 3.17mm-5mm, 4mm-5mm, 4mm-6mm, 5mm-5mm, 5mm-6mm, 6mm-6mm Universal Joint Outside Diameter: 11mm Universal Joint Length: 23mm Side Screw Fixing Hole: M4 5mm-8mm, 6mm-8mm, 6.35mm-8mm, 8mm-8mm Universal Joint Outside Diameter: 14mm Universal Joint Length: 35mm Side Screw Fixing Hole: M4 Fixed Clamp Spring Design 8mm-10mm, 10mm-10mm Universal Joint Outside Diameter: 16mm Universal Joint Length: 35mm Side Screw Fixing Hole: M4 Package Included : Universal Joint x 1 Screw x 2 Spanner x 1 _x000D_